1. Field of the Invention
The present invention relates generally to integrated circuit input and/or output and, more specifically, the present invention relates to the optical coupling of integrated circuit inputs and/or outputs.
2. Description of Related Art
Within the integrated circuit industry there is a continuing effort to increase integrated circuit speed as well as device density. One challenge that integrated circuit designers face with increasing circuit speeds and device densities is the increasingly significant propagation delays of circuit inputs and outputs due to the capacitive loading associated with circuit connections. At slower clock speeds, the capacitive loading on integrated circuit lines is generally not a significant factor. However, as newer integrated circuit design clock speeds continue to climb towards the gigahertz range and beyond, it is evident that one of the major bottlenecks for future integrated circuits, such as for example but not limited to microprocessors, off-chip caches, controllers, etc., is the input/output bandwidth and/or round trip delay between and within chips.
Prior attempts to address the capacitive loading problems associated with increased integrated circuit speeds and device densities have resulted in the use of larger and more powerful integrated circuit input and/or output drivers on the chip. An undesirable consequence of using larger input/output drivers is that the larger input/output drivers generally consume more power, dissipate more heat and occupy more valuable area on the integrated circuit die than smaller integrated circuit input/output drivers.
Other prior attempts to overcome traditional integrated circuit connection limitations have included the use of gallium arsenide (GaAs) technology-based optical interconnection techniques. For example, some approaches use GaAs laser diodes that are electrically modulated and switched. Other approaches use GaAs-built modulators that amplitude modulate a laser beam that passes through an integrated circuit. The modulation used in these prior approaches is based on electroabsorbtion through strained multi-layer grown molecular beam epitaxy (MBE) films in GaAs integrated circuits.
As can be appreciated by those skilled in the art, it is difficult to combine III-V-based technology, which includes GaAs, with standard silicon-based complementary metal oxide semiconductor (CMOS) technology, for example. Because many integrated circuits in production today and planned for the future use CMOS or other types of non-III-V technology, it may be impractical to use the above-described approaches in many cases.
An optical interconnection is disclosed. In one embodiment, the disclosed optical interconnection includes a semiconductor die having a first insulating layer disposed between a semiconductor substrate and a semiconductor layer. The optical interconnection also includes a first optical conduit disposed in the first insulating layer between the semiconductor substrate and the semiconductor layer to provide an optical path for light to travel through a back side of the semiconductor substrate, through the first optical conduit and through the semiconductor layer.
Additional features and benefits of the present invention will become apparent from the detailed description, figures and claims set forth below.